Although it is possible to isolate clones of T-lymphocytes which have specific cytotoxicity directed against autologous tumor cells, the techniques involved are laborious. More convenient assays for specific cytotoxic T-cells (CTLs) would simplify the study of immune response to tumors and would facilitate the investigation of systemic immune responses in cancer patients who are undergoing immunotherapy such as tumor vaccine therapy. The novel ELISPOT assay uses peripheral blood T-cells from patients which are stimulated by exposure in vitro to membranes derived from a surgically obtained sample of the same patient's cancer. In a previous we have shown that stimulation of T- cells of mice and men with cellular membranes is effective and specific. We have also observed that T-cells of patients undergoing a vaccination protocol with an array of cancers could be stimulated specifically by the membranes derived from those patients' cancers. In the present study we will expand this analysis to a larger number of cancer patients with a broader variety of cancers, and at different stages, to establish a baseline for evaluating immune response to tumors.